Snow melting mat



B. K. CUSTER, JR

July 22, 1958 SNOW MELTING MAT 2 Sheets-Sheet 1 Filed Aug. 14, 1957 Byron K. Custer, Jr.

30 JNVENTOR. I

BY WM EM July 22, 1958 B. K. CUSTER, JR 2,844,696

snow MELTING MAT all! 1 A I,

Byron K. Custer, J1:

INVENTOR.

United States Patent SNOW MELTING MAT Byron K. Custer, Jr., Johnstown, Pa. Application August 14, 1957, Serial No. 678,092

9 Claims. (Cl. 219-19) This invention relates to an electric heating device and more particularly to a novel snow melting mat.

The primary object of the present invention resides in the provision of a snow melting mat adapted to be used on steps, entrances to buildings, on walks or the like so as to remove snow and ice from these places by melting thereby reducing the possibilities of accidents occurring.

The concepts of this invention feature the use of means for not only thoroughly distributing the heat emanating from a heating coil embedded within the mat but for also grounding the mat so as to prevent the possibility of electrical shock while also providing an arrangement whereby a replaceable tread can be secured on the mat.

Still further objects and features of this invention reside in the provision of a snow melting mat that is simple in construction, efficient in use, capable of being made in any selected size and shape and which may be made separable so as to be readily assembled for use in conjunction with the protection of any particular area desired.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this snow melting mat, preferred embodiments of which have been illustrated in the accompanying drawings, by way of example only, wherein:

Figure 1 is a perspective view of an embodiment of the present invention shown in use protecting an entrance into a building including steps;

Figure 2 is a plan view of one of the sections of the snow melting mat comprising the present invention;

Figure 3 is an enlarged sectional detail view illustrating the connection between two sections of a snow melting mat constructed in accordance with the concepts with the present invention;

Figure 4 is a sectional detail view as taken along the plane of line 4-4 in Figure 2 illustrating on an enlarged scale the construction of the present invention and further illustrating the manner in which two of the sections of the mat may be secured together;

Figure 5 is a sectional detail view as taken along the plane of line 5-5 in Figure 2 and shown on an enlarged scale further details of construction of the mat;

Figure 6 is a perspective view of one of the connectors used for connecting the mat to a source of electrical current;

Figure 7 is a vertical sectional view as taken along the plane of line 7-7 in Figure 6;

Figure 8 is a plan view of a modified form of the invention; and

Figure 9 is an enlarged sectional detail view as taken along the plane of line 99 of Figure 8.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 10 is used to generally designate a snow melting mat arrangement in accordance with the concepts of the present invention. Each of the snow melting mat sections ice 2 as shown herein are substantially identical in construction and it is noted that the mat forming the protective means for one of the steps as indicated at '12 is formed of sections 14 and 16. Since these sections 14 and 16 of one of the arrangements of the snow melting mat which can be assembled so as to encompass any suitable area, it being noted that any number of the mats may be utilized in conjunction with each other, only the mat 12 will be considered further. The mat 12, see Figure 4, includes a main sheet 1'8 of rubber or other similar material having bonded to the underside thereof a layer of insulating type rubber or plastic as at 20. Embedded in the sheet 18 is a heating coil 22 which may be arranged in any suitable manner so as to cover a maximum area of the mat. It is noted that various types of arrangements such as spirals, labyrinths, or the like, may be utilized, the heating coil arrangement being best seen in Figure 2 with the heating coil 22 being seen in phantom liens. The heating coil 22 is formed of any suitable thermal resistance type wire and is connected to a pair of plugs as at 24vand 26 at one side of each of the mat sections and to a pair of sockets 28 and 30 at the other side of the mat section.

Positioned on the sheet 18 is a wire mesh or screen 32 of electrically conductive and heat conductive material such as iron, copper, brass, aluminum, or the like. Bonded to the sheet 18 is a tread 34 which sandwiches the screen 32 between the tread 34 and the sheet 18, the tread 34 being formed of any suitable material such as rubber or the like and being provided with alternate ridges and depressions as at 36 and 38 forming a section grip and drainage means for the surface of the mat. Thus there is provided a non-skid surface for the mat enabling the mat to be readily used in fair weather as well as foul.

Along the sides of each of the mat sections 14 and 16 are ground strips 40 and 42. Further, it is noted that the ground strips underlie extension portions 44 of the mat sections andoverlie extension portions 46 of the mat sections and engage and are connected to the screen 32 to ground the screen. The section 44 has enlarged recesses 48 in alignment with the apertures 50 in the ground strip 40 while the section 46 has enlarged recesses 52 therein in alignment with the aperture 54 through the ground strip 42. Bolts as at 56 extend through the aligned apertures 59 and 54 with the heads of the bolts being received in the cavities in the recesses 48 and with the nuts 58 being received in the recesses 52. Thus,

the mat sections are grounded to each other and electrically connected to each other due to the fact that the plugs 24 and 26 will be received in the recesses 28 and 30 of adjacent mat sections.

In order to connect the various mats as mat 12 to a source of electrical power, there is a cable 60 which is connected to a suitable source of electrical power through an outlet 62 and connectors as can be seen best in Figures 6 and 7 and indicated by reference numeral 64 are utilized. The connectors '64 are constructed of a body 66 of an insulative material and have sockets as at 68 and 70 therein to which the conductors 72 and 74 within the cable 60 are connected. The connectors 64 further are provided with ground strips 76 and a ground screen 78 is connected to the ground strip 76 and 92 with the plugs 94 and 96 being arranged in corresponding positions at the other side of the mat. In this form of the invention the sheet 98 has the heating coil ltlll embedded therein and the tread 102 is provided with alternate depressions 104 and raised surfaces 106 to provide the non-skid surface. The screen 108 is provided in much the same manner as in the other form of the invention and an under sheet 11% of suitable insulative material is provided. Of course, the ground strips 112 and- 114 are broken away in two places in lieu of just the one place as in the embodiment previously described.

As can be seen best in Figure 5, the tread 32 may have thickened portions as at 120 and 122 adjacent the front and rear of the mat. It is to be noted that the screen 32 or 1% performs three functions. This screen serves to distribute heat over the entire surface while serving as an electrical ground to protect users from electric shocks should the tread become worn and when welded or braced to the metal strips at the edge of each of the mats and forms part of a structural system which link the mats together and also prevents tearing.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and de-- scribed, and accordingly all suitable modifications and equivalents may be resorted to, falling Within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A melting mat comprising a sheet of electrically insulative material having an electrically conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said wire mesh and bonded to said wire mesh and said sheet sandwiching said wire mesh between said tread and said sheet, metallic ground strips secured to said mat, said Wire mesh being connected to said ground strips.

2. A melting mat comprising a sheet of electrically insulative material having an electric-ally conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said wire mesh and bonded to said wire mesh and said sheet sandwiching said Wire mesh between said tread and said sheet, said mat being formed in sections, each of said sections having metallic ground strips secured thereto on opposite sides thereof, said wire mesh being connected to said ground strips, adjacent of said ground strips being bolted together.

3. A melting mat comprising a sheet of electrically insulative material having an electrically conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said wire mesh and bonded to said wire mesh and said sheet sandwiching said wire mesh between said tread and said sheet, said mat being formed in sections, each of said sections having metallic ground strips secured thereto on opposite sides thereof, said wire mesh being connected to said ground strips, said sections each having sockets in one of said sides thereof and plugs on the other side thereof, adjacent of said 4 ground strips being bolted together hold plugs in sock ets adjacent thereto.

4. A melting mat comprising a sheet of electrically insulative material having an electrically conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said wire mesh and bonded to said wire mesh and said sheet sandwiching said wire mesh between said tread and said sheet, metallic ground strips secured to said mat, said wire mesh being connected to said ground strips, said sheet having sockets in one side thereof and plugs on another side thereof, said sockets and said plugs being connected to said heating coil.

5. A melting mat comprising a sheet of electrically insulative material having an electrically conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said 'wire mesh and banded thereto and to said sheet to sandwich the wire mesh between said tread and said sheet, said tread and the underlying wire mesh at one side of said mat, extending beyond said sheet and said sheet and the overlying mesh, at the other side of said mat, extending beyond said tread, and means on said mat for joining said mat with an adjacent mat having a complemental side overlapped therewith so as to electrically connect the wire mesh of said mats.

6. A melting mat comprising a sheet of electrically insulative material having an electrically conductive heating coil embedded therein, a heat conductive wire mesh overlying said sheet, a tread of electrically insulative material positioned over said wire mesh and handed thereto and to said sheet to sandwich the wire mesh between said tread and said sheet, said tread, at one side of said mat, extending beyond said sheet and said sheet, at the other side of said mat, extending beyond said tread, said wire mesh having exposed extension portions at opposite sides of said mat, one such portion underlying the extended tread at said one side of the mat and the other portion overlying the extended sheet at said other side of the mat, whereby said mat may be overlapped with a similar mat with the wire meshes thereof in electrical communication.

7. The assembly as defined in and by claim 6 wherein said extension portions of the Wire mesh are in the form of ground straps extending along corresponding sides of said mat.

8. The assembly as defined in and by claim 7 wherein said ground straps are apertured to receive fastening elements therethrough for joining adjacent mats and electrically connecting corresponding ground straps thereof.

9. The assembly as defined in and by claim 5 wherein opposite sides of said mat are provided With a socket and a plug respectively, said socket and plug being electrically connected to said heating coil.

References Cited in the file of this patent UNITED STATES PATENTS 1,632,651 Hubbard June 14, 1927 2,138,217 Sutter Nov. 29, 1938 2,497,998 Lee Feb. 21, 1951 

